Hi Moinur thanks for posting on the Community!

Unfortunately it is not currently possible to make the document non-editable if you are the document owner. Would you mind adding your idea to our feature request form? Ideas submitted to this form are passed on to the product development team for their consideration.

As a workaround I would recommend that you click and drag to select all the shapes in your flowchart and then right-click and select Group. This will group all of the shapes in your flowchart together so that you will no longer be prompted to move individual shapes. Please refer to this Grouping blog post for more details on this functionality that you can use within the document you own.

If you are sharing your document with other Lucid users I recommend sharing it with view-only permissions. Check out our Sharing article or our Publish your Lucidchart document article if you are interested in these options.